App Case Study: Daily Grid

Zac Zimmerman never expected a newsletter to change his weekend plans. As a full-stack software engineer working primarily with Python and C, he'd always dreamed of creating a mobile app but never found the time to dive into native mobile development. That changed when he received a competition announcement from Vibecode, a platform he'd signed up for months earlier but never used.

"I've always wanted to develop a mobile app, like since I was in high school," Zimmerman explained. He and his college roommates had sketched app ideas on whiteboards, even taking Swift courses, but without modern AI assistance, their projects never progressed beyond basic mockups. The Vibecode Holiday Challenge offered something different: a $12 credit and a clear deadline that made the project feel achievable.

The process

Inspiration struck while Zimmerman was out celebrating his wife's birthday. Drawing from his love of New York Times and LinkedIn puzzle games, combined with his wife's passion for room decoration apps, he conceived a hybrid concept. The result was Daily Grid, a puzzle game based on LinkedIn's Queen's game but with a unique Christmas tree-shaped grid for the December theme.

The initial build consumed his weekend—approximately 20 hours split between Saturday evening and Sunday, including time spent creating Photoshopped assets. "I get into focus mode and just go," he said.

And it paid off. Out of 49 entrants, Zimmerman impressively finished third.

But transforming the contest entry into an App Store-ready product required significantly more work: another 60 to 80 hours over three weeks, including securing a domain, creating a privacy policy website, and navigating Apple's developer approval process.

Zimmerman's business model prioritizes accessibility over profit. Like the New York Times games, anyone can play the daily puzzle for free. Premium subscribers paying $5 monthly unlock past puzzles, previous themes, and exclusive decorations. "My focus here wasn't so much to make money," he admitted. The real reward comes from his family group chat, where everyone shares their daily completion times each morning.

Advice for aspiring vibe coders

For aspiring Vibecode App developers, Zimmerman emphasizes market research first: "Find users that are willing to test it and actually want it" before spending money on development. He also stresses the importance of knowing when to use different AI models to balance quality and cost.

Having made exactly $0 so far, Zimmerman remains undeterred. He's 75% through adding a February theme and recently pushed his first update.